Algebra
posted by Sara .
A box with a square base and no top is to be made from a square piece of cardboard by cutting 4in squares from each corner and folding up the sides... the box is told 100 in cube, how big a piece of cardboard is needed?

If you mean "The box has a total volume of 100 in^3, then
(1) The sides of the box are 4 in high, so the base area must be 25 in^2
(2) That means the box sides are 5 inches long
(3) The original cardboard square piece must be 5 + 4 + 4 = 13 inches on a side, so that you will have a 5inchsquare base when the 4inchsquare corners are cut off 
A rectangle is 20 inches tall it's area is 260 inches what is the width